What is the difference between a User Story and a Feature in Agile terminology?
I guess a feature could be something like "credit card authorization", while a user story may be "authorize credit card for paypal".
So, is a user story a subset of a feature?
Answer
Yes, something like a subset. This article is a good read:
Features vs Stories
Excerpt:
I realized today that I hadn't made explicit the difference in my mind between features and stories and it's an important difference. Essentially, a feature is a group of stories that are related and deliver a package of functionality that end users would generally expect to get all at once. For instance, inline table resizing is a feature (note: this is the ability to drag to resize tables, rows and columns – try it in Word). In the first pass, you'd probably have a single story for inline resizing of tables, but it would be too big to estimate. So you break it down into three stories, resize columns, resize rows and resize the table itself.